IHEDocumentList.xsl used to be found into dcm4chee-rid.war. Since dcm4chee-web3 became the default GUI, IHEDocumentList.xsl was moved to server/default/conf/dcm4chee-rid/
But unfortunately, there is no way to indicate this path while configuring service=dcm4chee-rid. This is due to the fact that the path one can write there is automatically prefixed by http://host:port/rid/

Workaround: copy back IHEDocumentList.xsl and common.xsl into dcm4chee-rid.war, in a sub folder called xsl, so that the path correspond to the default relative path, which wasn't ever modified (xsl/IHEDocumentList.xsl)